Composition and method for treating substrate

ABSTRACT

Objects of the present invention are to provide a composition having excellent dissolving ability for a transition metal-containing substance (particularly, a Ru-containing substance) and to provide a method for treating a substrate. The composition according to an embodiment of the present invention contains at least one iodic acid compound selected from the group consisting of periodic acid, iodic acid, and salts thereof, and a compound represented by Formula (1).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of PCT International Application No.PCT/JP2021/028902 filed on Aug. 4, 2021, which claims priority under 35U.S.C. § 119(a) to Japanese Patent Application No. 2020-148338 filed onSep. 3, 2020. The above applications are hereby expressly incorporatedby reference, in their entirety, into the present application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a composition and a method for treatinga substrate.

2. Description of the Related Art

With the miniaturization of semiconductor products, it is increasinglyrequired that a step of removing unnecessary transition metal-containingsubstances on a substrate in a semiconductor product manufacturingprocess be performed with high efficiency and high accuracy.

Generally, it is widely known that etching or a method of removingforeign substances having adhered to a solid surface is performed usinga composition (etchant) dissolving unnecessary transitionmetal-containing substances in a step of removing unnecessary transitionmetal-containing substances on a substrate.

For example, JP2001-240985A discloses a treatment liquid containing aperiodic acid and a tetramethylammonium hydroxide salt.

SUMMARY OF THE INVENTION

In recent years, it has been required that a further enhanced dissolvingability be exhibited to an unnecessary transition metal-containingsubstance (particularly, a ruthenium-containing substance (Ru-containingsubstance)) in a composition in a case where the unnecessary transitionmetal-containing substance on a substrate is removed.

As a result of examining a transition metal-containing substance(particularly, a Ru-containing substance) by using the compositiondisclosed in JP2001-240985A, the inventors of the present invention havefound that the composition exhibits an insufficient dissolving abilityto the transition metal-containing substance (particularly, aRu-containing substance) and has a room for further improvement of thedissolving ability.

Therefore, an object of the present invention is to provide acomposition having excellent dissolving ability for a transitionmetal-containing substance (particularly, a Ru-containing substance).

Another object of the present invention is to provide a method fortreating a substrate by using the composition.

In order to achieve the above object, the inventors of the presentinvention carried out intensive studies. As a result, the inventors havefound that the objects can be achieved by the following constitution.

[1] A composition containing at least one iodic acid compound selectedfrom the group consisting of periodic acid, iodic acid, and saltsthereof, and a compound represented by Formula (1) that will bedescribed later.

The composition described in [1], further containing a chloride ion.

The composition described in [2], in which a content of the chloride ionis 1 ppt by mass to 1% by mass with respect to a total mass of thecomposition.

The composition described in [2] or [3], in which a mass ratio of acontent of the iodic acid compound to the content of the chloride ion is1.0 × 10⁴ or more.

The composition described in any one of [1] to [4], in which a contentof the iodic acid compound is 0.01% to 5.00% by mass with respect to atotal mass of the composition.

The composition described in any one of [1] to [5], in which the numberof carbon atoms in an alkyl group is 1 to 15.

The composition described in any one of [1] to [6], in which the totalnumber of carbon atoms in R¹ to R⁴ in Formula (1) is 4 to 15.

The composition described in any one of [1] to [7], in which R¹ to R⁴each represent an alkyl group selected from the group consisting of analkyl group having one carbon atom which may have a substituent and analkyl group having two carbon atoms which may have a substituent, atleast one of R¹, R², R³, or R⁴ is an alkyl group having one carbon atomwhich may have a substituent, and at least one of R¹, R², R³, or R⁴ isan alkyl group having two carbon atoms which may have a substituent.

The composition described in any one of [1] to [7], in which thecompound represented by Formula (1) includes at least one compoundselected from the group consisting of an ethyltrimethylammonium salt, adiethyldimethylammonium salt, a methyltriethylammonium salt, atrimethyl(hydroxyethyl)ammonium salt, adimethylbis(2-hydroxyethyl)ammonium salt, amethyltris(2-hydroxyethyl)ammonium salt, a methyltributylammonium salt,a dimethyldipropylammonium salt, a benzyltrimethylammonium salt, abenzyltriethylammonium salt, and a triethyl(hydroxyethyl)ammonium salt.

The composition described in any one of [1] to [9], in which n inFormula (1) is 1.

The composition described in any one of [1] to [10], in which X^(n-) inFormula (1) is a hydroxide ion, a chloride ion, a fluoride ion, or abromide ion.

The composition described in any one of [1] to [11], in which a contentof the compound represented by Formula (1) is 0.001% to 2.00% by masswith respect to a total mass of the composition.

The composition described in any one of [1] to [12], in which a pH ofthe composition is 3.0 to 9.0.

The composition described in any one of [1] to [13], in which a pH ofthe composition is 4.0 to 8.0.

The composition described in any one of [1] to [14], in which thecomposition is used for removing a ruthenium-containing substance on asubstrate.

A method for treating a substrate, including a step A of removing aruthenium-containing substance on a substrate by using the compositiondescribed in any one of [1] to [15].

The method for treating a substrate described in [16], in which the stepA is a step A1 of performing a recess etching treatment on aruthenium-containing wiring line disposed on a substrate by using thecomposition, a step A2 of removing a ruthenium-containing film at anouter edge portion of a substrate, on which the ruthenium-containingfilm is disposed, by using the composition, a step A3 of removing aruthenium-containing substance attached to a back surface of asubstrate, on which a ruthenium-containing film is disposed, by usingthe composition, a step A4 of removing a ruthenium-containing substanceon a substrate, which has undergone dry etching, by using thecomposition, or a step A5 of removing a ruthenium-containing substanceon a substrate, which has undergone a chemical mechanical polishingtreatment, by using the composition.

According to the present invention, it is possible to provide acomposition having an excellent dissolving ability for a transitionmetal-containing substance (particularly, a Ru-containing substance).

Furthermore, according to an embodiment of the present invention, it ispossible to provide a method for treating a substrate by using thecomposition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional top view showing an example of anobject to be treated used in a step A1.

FIG. 2 is a schematic cross-sectional top view showing an example of anobject to be treated having undergone the step A1.

FIG. 3 is a schematic view showing an example of an object to be treatedused in a step A2.

FIG. 4 is a schematic cross-sectional view showing an example of anobject to be treated used in a step A4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be specifically described.

The following configuration requirements will be described based ontypical embodiments of the present invention, but the present inventionis not limited to the embodiments.

In the present specification, a range of numerical values describedusing “to” means a range including numerical values listed before andafter “to” as a lower limit and an upper limit.

In the present specification, in a case where there are two or morekinds of components corresponding to a certain component, “content” ofsuch a component means the total content of the two or more kinds ofcomponents.

In the present specification, “exposure” is not particularly limited,and includes exposure using a mercury lamp, far ultraviolet raysrepresented by an excimer laser, X-rays, Extreme Ultraviolet (EUV)light, and the like and drawing by particle beams such as electron beamsand ion beams.

Unless otherwise specified, a compound described in the presentspecification may include structural isomers (compounds having the samenumber of atoms and different structures), optical isomers, andisotopes. In addition, a compound may include one kind of isomer andisotope or two or more kinds of isomers and isotopes.

In the present specification, a dry etching residue is a by-productgenerated as a result of performing dry etching (for example, plasmaetching). For example, the dry etching residue refers to an organicresidue derived from a photoresist, a Si-containing residue, and ametal-containing residue (for example, a transition metal-containingresidue).

Composition

The composition according to an embodiment of the present inventioncontains at least one iodic acid compound (hereinafter, also simplycalled “iodic acid compound”) selected from the group consisting ofperiodic acid, iodic acid, and salts thereof, and a compound representedby Formula (1) (hereinafter, also called “specific compound”).

The mechanism through which the objects of the present invention areachieved by the use of the composition according to the embodiment ofthe present invention is unclear. According to the inventors of thepresent invention, the mechanism is assumed to be as below.

Presumably, because the composition contains the iodic acid compound andthe specific compound, the compounds may bring about a synergisticeffect, which can realize an excellent dissolving ability for atransition metal-containing substance (particularly, a Ru-containingsubstance).

Hereinafter, further improving the dissolving ability of the compositionfor a transition metal-containing substance (particularly, aRu-containing substance) will be also described as further improving theeffect of the present invention.

Iodic Acid Compound

The composition contains an iodic acid compound.

The iodic acid compound is at least one compound selected from the groupconsisting of periodic acid, iodic acid, and salts thereof.

Examples of the iodic acid compound include orthoperiodic acid (H₅IO₆),metaperiodic acid (HIO₄), iodic acid (HIO₃), and salts thereof.

Among the above, the iodic acid compound preferably includes at leastone compound selected from the group consisting of orthoperiodic acid,metaperiodic acid, and iodic acid, more preferably includes at least onecompound selected from the group consisting of orthoperiodic acid andmetaperiodic acid, and even more preferably includes orthoperiodic acid.

One kind of iodic acid compound may be used alone, or two or more kindsof iodic acid compounds may be used in combination.

In view of further improving the effect of the present invention, thecontent of the iodic acid compound is with respect to the total mass ofthe composition is 0.00001% by mass or more in many cases, preferably0.001% to 10.00% by mass, more preferably 0.01% to 5.00% by mass, andeven more preferably 0.1% to 2.00% by mass.

Compound Represented by Formula (1)

The composition contains a compound represented by Formula (1) (specificcompound).

In Formula (1), R¹ to R⁴ each independently represent an alkyl groupwhich may have a substituent.

The alkyl group may be linear, branched, or cyclic, and is preferablylinear.

In view of further improving the effect of the present invention, thenumber of carbon atoms in the alkyl group is preferably 1 to 20, morepreferably 1 to 15, even more preferably 1 to 10, particularlypreferably 1 to 5, and most preferably 1 or 2.

In view of further improving the effect of the present invention, thetotal number of carbon atoms in R¹ to R⁴ is preferably 4 to 20, morepreferably 4 to 15, and even more preferably 4 to 7. The total number ofcarbon atoms in R¹ to R⁴ means the sum of carbon atoms in R¹, R², R³,and R⁴.

Examples of the substituent that the alkyl group has include a hydroxygroup, a carboxy group, an amino group, an oxo group, a phosphonic acidgroup, a sulfo group, an aryl group, a heteroaryl group, and a mercaptogroup. As the substituent, among these, a hydroxy group or an aryl groupis preferable.

The number of substituents that the alkyl group has is preferably 0 to5, more preferably 0 to 3, and even more preferably 0 or 1.

n represents an integer of 1 to 3.

n is preferably an integer of 1 or 2, and more preferably 1.

R¹ to R⁴ do not represent the same group all together. For example, in acase where all of R¹ to R⁴ represent a methyl group, because R¹ to R⁴are the same group, the condition of “R¹ to R⁴ do not represent the samegroup all together” is not satisfied. On the other hand, in a case whereall of R¹ to R³ are methyl groups and R⁴ is an ethyl group, because notall R¹ to R⁴ are the same group, the condition of “R¹ to R⁴ do notrepresent the same group all together” is satisfied. Note that in a casewhere at least either the type of substituent or the type of alkyl groupis different, the groups are not the same group. That is, in a casewhere two groups differ from each other in terms of at least the type ofsubstituent or the type of alkyl group, the groups are regarded asdifferent groups. For example, because there is a difference in overallstructure between an ethyl group and a hydroxyethyl group, these groupsare not the same group.

The aforementioned “R¹ to R⁴ do not represent the same group alltogether” in other words means that 4 groups represented by R¹ to R⁴represent at least two kinds of groups. For example, in a case where allof R¹ to R³ are methyl groups and R⁴ is an ethyl group, 4 groupsrepresented by R¹ to R⁴ represent two types of groups, a methyl groupand an ethyl group.

Examples of aspects that R¹ to R⁴ can take include an aspect in whichamong the 4 groups represented by R¹ to R⁴, 3 groups represented by R¹to R³ are the same group and 1 group represented by R⁴ is a groupdifferent from the above 3 groups. The examples also include an aspectin which among 4 groups represented by R¹ to R⁴, 2 groups represented byR¹ and R² are the same group and 2 groups represented by R³ and R⁴ arethe same group, but the group represented by R¹ and R² is different fromthe group represented by R³ and R⁴. In addition, all of 4 groupsrepresented by R¹ to R⁴ may be different groups.

R¹ to R⁴ are preferably an alkyl group selected from the groupconsisting of an alkyl group having one carbon atom which may have asubstituent and an alkyl group having two carbon atoms which may have asubstituent, at least one of R¹, R², R³, or R⁴ is preferably an alkylgroup having one carbon atom which may have a substituent, and at leastone of R¹, R², R³, or R⁴ is preferably an alkyl group having two carbonatoms which may have a substituent.

Examples of R¹ to R⁴ include an alkyl group such as a methyl group, anethyl group, a propyl group, a butyl group, a dodecyl group, or atetradodecyl group; a hydroxyalkyl group (an alkyl group having ahydroxy group) such as a hydroxymethyl group, a hydroxyethyl group, or ahydroxybutyl group; and an arylalkyl group (an alkyl group having anaryl group) such as a benzyl group or phenethyl group.

As R¹ to R⁴, among the above, in view of further improving the effect ofthe present invention, an alkyl group, a hydroxyalkyl group, or anarylalkyl group is preferable, and an alkyl group or a hydroxyalkylgroup is more preferable.

X^(n-) represents an n-valent anion.

n has the same definition as n described above, and the suitable aspectsthereof are also the same.

The n-valent anion is not particularly limited, and examples thereofinclude a hydroxide ion, a halide ion, a cyanide ion, an acetate ion, atrifluoroacetate ion, a hydrogen sulfate ion, a sulfate ion, a sulfiteion, a sulfonate ion, a thiosulfate ion, a carbonate ion, an oxalateion, a hydrogen phosphate ion, and a phosphate ion.

As X^(n-), among the above, in view of further improving the effect ofthe present invention, a hydroxide ion or a halide ion is preferable, ahydroxide ion, a chloride ion, a fluoride ion, or a bromide ion is morepreferable, and a hydroxide ion or a chloride ion is even morepreferable.

Examples of the specific compound include an ethyltrimethylammoniumsalt, a diethyldimethylammonium salt, a methyltriethylammonium salt, atrimethyl(hydroxyethyl)ammonium salt, a methyltributylammonium salt, adimethyldipropylammonium salt, a benzyltrimethylammonium salt, abenzyltriethylammonium salt, a triethyl(hydroxyethyl)ammonium salt, adodecyltrimethylammonium salt, a tetradecyltrimethylammonium salt, ahexadecyltrimethylammonium salt, a methyltri(hydroxyethyl)ammonium salt,a benzyltrimethylammonium salt, a triethyl(hydroxyethyl)ammonium salt, abishydroxyethyldimethylammonium salt, a trimethylpropylammonium salt, anisopropyltrimethylammonium salt, a butyltrimethylammonium salt, atriethylpropylammonium salt, an isopropyltriethylammonium salt, abutyltriethylammonium salt, a methyltripropylammonium salt, anethyltripropylammonium salt, a butyltripropylammonium salt, anethyltributylammonium salt, a propyltributylammonium salt, adiisopropyldimethylammonium salt, a dibutyldimethylammonium salt, adiethyldipropylammonium salt, a diethyldiisopropylammonium salt, adiethyldibutylammonium salt, an ethylmethylpropylbutylammonium salt, anethylmethylisopropylbutylammonium salt, an ethylmethyldipropylammoniumsalt, an ethylmethyldiisopropylammonium salt, adimethylbis(2-hydroxyethyl)ammonium salt, amethyltris(2-hydroxyethyl)ammonium salt, and anethylmethyldibutylammonium salt.

Among these, the specific compound preferably includes at least onecompound selected from the group consisting of an ethyltrimethylammoniumsalt, a diethyldimethylammonium salt, a methyltriethylammonium salt, atrimethyl(hydroxyethyl)ammonium salt, adimethylbis(2-hydroxyethyl)ammonium salt, amethyltris(2-hydroxyethyl)ammonium salt, a methyltributylammonium salt,a dimethyldipropylammonium salt, a benzyltrimethylammonium salt, abenzyltriethylammonium salt, a triethyl(hydroxyethyl)ammonium salt, adodecyltrimethylammonium salt, a tetradecyltrimethylammonium salt, and ahexadecyltrimethylammonium salt, more preferably includes at least onecompound selected from the group consisting of an ethyltrimethylammoniumsalt, a diethyldimethylammonium salt, adimethylbis(2-hydroxyethyl)ammonium salt, amethyltris(2-hydroxyethyl)ammonium salt, a methyltriethylammonium salt,a trimethyl(hydroxyethyl)ammonium salt, a methyltributylammonium salt, adimethyldipropylammonium salt, a benzyltrimethylammonium salt, abenzyltriethylammonium salt, and a triethyl(hydroxyethyl)ammonium salt,even more preferably includes at least one compound selected from thegroup consisting of an ethyltrimethylammonium salt, adiethyldimethylammonium salt, a methyltriethylammonium salt, atrimethyl(hydroxyethyl)ammonium salt, adimethylbis(2-hydroxyethyl)ammonium salt, and amethyltris(2-hydroxyethyl) ammonium salt, and particularly preferablyincludes at least one compound selected from the group consisting of anethyltrimethylammonium salt, a diethyldimethylammonium salt, amethyltriethylammonium salt, and a trimethyl(hydroxyethyl)ammonium salt.

The above salt has the same definition as the aforementioned X^(n-), andsuitable ranges thereof are also the same.

One kind of specific compound may be used alone, or two or more kinds ofspecific compounds may be used in combination.

The content of the specific compound with respect to the total mass ofthe composition is preferably 0.0001% to 5.00% by mass, more preferably0.001% to 2.00% by mass, and even more preferably 0.001% to 1.50% bymass.

Optional Components

The composition may contain optional components in addition to theaforementioned components contained in the composition.

Examples of the optional components include a chloride ion, a solvent, apH adjuster, and a surfactant.

Hereinafter, the optional components will be described.

Chloride Ion

The composition may contain a chloride ion (Cl⁻).

The chloride ion may be a chloride ion represented by the aforementionedX^(n-).

In a case where the composition contains a chloride ion, a metal residueremovability of the composition can be improved.

In view of improving the metal residue removability, the content of thechloride ion with respect to the total mass of the composition ispreferably 1 ppt by mass to 1% by mass, more preferably 0.0001 to 7,000ppm by mass, even more preferably 0.001 to 10 ppm by mass, andparticularly preferably 0.001 to 0.1 ppm by mass.

In view of further improving the effect of the present invention, a massratio of the content of the iodic acid compound to the content of thechloride ion (content of iodic acid compound/content of chloride ion) ispreferably 0.1 or more, more preferably 1.0 × 10³ or more, and even morepreferably 1.0 × 10⁴ or more. The upper limit thereof is notparticularly limited, but is preferably 1.0 × 10¹⁰ or less and morepreferably 1.0 × 10⁸ or less.

The content of the chloride ion in the composition is determined by ionchromatography. Specifically, examples of the ion chromatography deviceinclude Dionex ICS-2100 manufactured by Thermo Fisher Scientific Inc. Ina case where the content of the chloride ion is low, the content of thechloride ion may be measured after the composition is concentrated usinga concentrator column. In a case where the composition of raw materialsis known, the content of the chloride ion may be calculated and obtainedfrom the amount of the raw materials added.

The chloride ion may be added, for example, by a method of adding acompound containing a chloride ion to the composition during thepreparation of the composition, immediately before treating a substrate,or the like. In addition, the chloride ion may be incorporated into thecomposition by using a raw material containing a trace of chloride ionas an impurity in preparing the composition.

Examples of the compound containing a chloride ion include a compoundwhich dissociates in the composition to form a chloride ion and acation.

Examples of the compound that produces a chloride ion and a cationinclude the specific compound and hydrochloric acid or a salt thereof(for example, a salt with an alkali metal and a salt with an alkalineearth metal).

Solvent

The composition may contain a solvent.

Examples of the solvent include water and an organic solvent. Amongthese, water is preferable.

As water, water having undergone a purification treatment such asdistilled water, deionized water, or ultrapure water is preferable, andultrapure water used for manufacturing semiconductors is morepreferable. Water to be incorporated into the composition may contain atrace of components that are unavoidably mixed in.

The content of water with respect to the total mass of the compositionis preferably 50% by mass or more, more preferably 65% by mass or more,and even more preferably 75% by mass or more. The upper limit thereof isnot particularly limited. The upper limit with respect to the total massof the composition is preferably 99.999% by mass or less, and morepreferably 99.9% by mass or less.

As the organic solvent, a water-soluble organic solvent is preferable.

Examples of the water-soluble organic solvent include an ether-basedsolvent, an alcohol-based solvent, a ketone-based solvent, anamide-based solvent, a sulfur-containing solvent, and a lactone-basedsolvent. The water-soluble organic solvent is preferably an organicsolvent that can be mixed with water at an arbitrary ratio.

The ether-based solvent is not particularly limited as long as it is acompound having an ether bond (—O—). Examples thereof include diethylether, diisopropyl ether, dibutyl ether, t-butyl methyl ether,cyclohexyl methyl ether, tetrahydrofuran, diethylene glycol, dipropyleneglycol, triethylene glycol, polyethylene glycol, alkylene glycolmonoalkyl ether (ethylene glycol monomethyl ether, ethylene glycolmonobutyl ether, propylene glycol monomethyl ether, diethylene glycolmonomethyl ether, dipropylene glycol monomethyl ether, tripropyleneglycol monomethyl ether, and diethylene glycol monobutyl ether), andalkylene glycol dialkyl ether (diethylene glycol diethyl ether,diethylene glycol dipropyl ether, diethylene glycol dibutyl ether,triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether,tetraethylene glycol diethyl ether, ethylene glycol dimethyl ether,diethylene glycol dimethyl ether, and triethylene glycol dimethylether).

The number of carbon atoms in the ether-based solvent is preferably 3 to16, more preferably 4 to 14, and even more preferably 6 to 12.

Examples of the alcohol-based solvent include methanol, ethanol,1-propanol, 2-propanol, 1-butanol, 2-butanol, ethylene glycol, propyleneglycol, glycerin, 1,6-hexanediol, cyclohexanediol, sorbitol, xylitol,2-methyl-2,4-pentanediol, 1,3-butanediol, and 1,4-butanediol.

The number of carbon atoms in the alcohol-based solvent is preferably 1to 8, and more preferably 1 to 4.

Examples of the ketone-based solvent include acetone, methyl ethylketone, methyl isobutyl ketone, and cyclohexanone.

Examples of the amide-based solvent include formamide,monomethylformamide, dimethylformamide, acetamide, monomethylacetamide,dimethylacetamide, monoethylacetamide, diethylacetamide, andN-methylpyrrolidone.

Examples of the sulfur-containing solvent include dimethyl sulfone,dimethyl sulfoxide, and sulfolane.

Examples of the lactone-based solvent include γ-butyrolactone andδ-valerolactone.

One kind of organic solvent may be used alone, or two or more kinds oforganic solvents may be used. In a case where two or more kinds oforganic solvents are used, the total content of two or more kinds oforganic solvents is preferably within the following range.

The content of the organic solvent is preferably 0.1% to 10% by masswith respect to the total mass of the composition.

pH Adjuster

The composition may contain a pH adjuster.

Examples of the pH adjuster include a basic compound and an acidiccompound. The pH adjuster is appropriately selected depending on thetarget pH of the composition.

Basic Compound

The basic compound is a compound that exhibits alkalinity (pH higherthan 7.0) in an aqueous solution.

Examples of the basic compound include an organic base, an inorganicbase, and a salt of these.

Examples of the organic base include a quaternary ammonium salt, a saltof an alkylamine compound and a derivative thereof, an alkanolaminecompound and a salt thereof, an amine oxide compound, a nitro compound,a nitroso compound, an oxime compound, a ketoxime compound, an aldoximecompound, and a lactam compound, and an isocyanide compound.

The quaternary ammonium salt as a pH adjuster is a compound differentfrom the specific compound.

The quaternary ammonium salt is a quaternary ammonium cation-containingsalt formed by the substitution of a nitrogen atom with four identicalhydrocarbon groups (preferably alkyl groups).

Examples of the quaternary ammonium salt include a hydroxide, afluoride, a bromide, an iodide, an acetate, and a carbonate.

As the quaternary ammonium salt, tetramethylammonium hydroxide (TMAH),tetraethylammonium hydroxide (TEAH), tetrabutylammonium hydroxide(TBAH), tetrapropylammonium hydroxide (TPAH), ortetra(hydroxyethyl)ammonium hydroxide is preferable, and TMAH, TEAH,TPAH, or TBAH is more preferable.

Examples of the inorganic base include alkali metal hydroxides such assodium hydroxide and potassium hydroxide, alkaline earth metalhydroxides, and ammonia or a salt thereof.

As the basic compound, among the above, in view of few metal residuesafter use, economics, stability of the composition, and the like, aquaternary ammonium hydroxide is preferable, TMAH or TEAH is morepreferable, and TEAH is even more preferable.

Acidic Compound

The acidic compound is an acidic compound that exhibits acidity (pH ofless than 7.0) in an aqueous solution.

Examples of the acidic compound include an inorganic acid, an organicacid, and a salt of these.

Examples of the inorganic acid include sulfuric acid, hydrochloric acid,phosphoric acid, nitric acid, hydrofluoric acid, perchloric acid,hypochlorous acid, and salts thereof. As the inorganic acid, sulfuricacid, hydrochloric acid, phosphoric acid, or nitric acid is preferable,and nitric acid, sulfuric acid, or hydrochloric acid is more preferable.

Examples of organic acid include carboxylic acid, sulfonic acid, andsalts thereof.

Examples of the carboxylic acid include lower aliphatic monocarboxylicacids (having one to four carbon atoms) such as formic acid, aceticacid, propionic acid, and butyric acid, and salts thereof.

Examples of the sulfonic acid include methanesulfonic acid (MSA),benzenesulfonic acid, p-toluenesulfonic acid (tosylic acid), and a saltof these.

As the acidic compound, sulfuric acid, hydrochloric acid, phosphoricacid, nitric acid, or sulfonic acid or salts thereof are preferable, andsulfuric acid, hydrochloric acid, phosphoric acid, methanesulfonic acid,or p-toluenesulfonic acid is more preferable.

One kind of pH adjuster may be used alone, or two or more kinds of pHadjusters may be used in combination.

Furthermore, a commercially available pH adjuster or a pH adjusterappropriately synthesized by a known method may also be used.

The content of the pH adjuster with respect to the total mass of thecomposition is preferably 0.1% by mass or more, and more preferably 0.5%by mass or more. The upper limit thereof is not particularly limited,but is preferably 20.0% by mass or less with respect to the total massof the composition.

It is also preferable to adjust the content of the pH adjuster withinthe aforementioned suitable range so that the pH of the compositionfalls into the suitable range which will be described later.

Surfactant

The composition may contain a surfactant.

The surfactant is not particularly limited as long as it is a compoundhaving a hydrophilic group and a hydrophobic group (lipophilic group) inone molecule. Examples of the surfactant include an anionic surfactant,a cationic surfactant, and a nonionic surfactant.

The hydrophobic group of the surfactant is not particularly limited, andexamples thereof include an aliphatic hydrocarbon group, an aromatichydrocarbon group, and a combination of these.

In a case where the hydrophobic group has an aromatic hydrocarbon group,the number of carbon atoms in the hydrophobic group is preferably 6 ormore, and more preferably 10 or more.

In a case where the hydrophobic group does not include an aromatichydrocarbon group and is composed of only an aliphatic hydrocarbongroup, the number of carbon atoms in the hydrophobic group is preferably8 or more, and more preferably 10 or more. The upper limit of the numberof carbon atoms in the hydrophobic group is not particularly limited,and is preferably 24 or less, and more preferably 20 or less.

Examples of the anionic surfactant include an anionic surfactant havingat least one kind of hydrophilic group selected from the groupconsisting of a sulfonic acid group, a carboxy group, a sulfuric acidester group, and a phosphonic acid group in the molecule.

Examples of the anionic surfactant having a sulfonic acid group includealkylsulfonic acid, alkylbenzenesulfonic acid, alkylnaphthalenesulfonicacid, alkyldiphenylether sulfonic acid, fatty acid amide sulfonic acid,and salts thereof.

Examples of the anionic surfactant having a carboxylic acid groupinclude polyoxyethylene alkyl ether carboxylic acid, polyoxyethylenealkyl ether acetic acid, polyoxyethylene alkyl ether propionic acid, afatty acid, and salts thereof.

Examples of salts of the anionic surfactant include an ammonium salt, asodium salt, a potassium salt, and a tetramethylammonium salt.

The cationic surfactant is not particularly limited as long as it is acompound having a cationic hydrophilic group and the aforementionedhydrophobic group. Examples of the cationic surfactant include aquaternary ammonium salt-based surfactant and an alkyl pyridium-basedsurfactant.

One kind of surfactant may be used alone, or two or more kinds ofsurfactants may be used.

The content of the surfactant with respect to the total mass of thecomposition is preferably 0.01% by mass or more, and more preferably0.03% by mass or more. The upper limit thereof is not particularlylimited. In view of suppressing foaming of the composition, the upperlimit of the content of the surfactant with respect to the total mass ofthe composition is preferably 10% by mass or less, and more preferably5% by mass or less.

Abrasive Particles

It is preferable that the composition substantially do not containabrasive particles.

The abrasive particles mean particles that are contained in a polishingliquid used for performing a polishing treatment on a semiconductorsubstrate and have an average primary particle diameter of 5 nm or more.

For the composition, “substantially does not contain abrasive particles”means that in a case where the composition is measured using acommercially available measurement device for a light scattering-typeparticle measurement method in a liquid, the number of abrasiveparticles having an average primary particle diameter of 5 nm or morecontained in 1 mL of the composition is 10 or less.

Examples of the abrasive particles include inorganic abrasive grainssuch as silica (including colloidal silica and fumed silica), alumina,zirconia, ceria, titania, germania, manganese oxide, and siliconcarbide; and organic abrasive grains such as polystyrene, polyacryl, andpolyvinyl chloride.

The content of the abrasive particles is measured using a commerciallyavailable measurement device for a light scattering-type particlemeasurement method in a liquid by using a laser as a light source.

The average primary particle diameter of particles such as abrasiveparticles is determined by measuring particle diameters (circularequivalent diameters) of 1,000 primary particles randomly selected froman image captured using a transmission electron microscope TEM2010(acceleration voltage 200 kV) manufactured by JEOL Ltd., and calculatingthe arithmetic mean thereof. The circular equivalent diameter is thediameter of a virtual perfect circle assumed to have the same projectedarea as the projected area of a particle observed.

Examples of the method for removing the abrasive particles from thecomposition include a purification treatment such as filtering.

pH

The pH of the composition is not particularly limited and is, forexample, in a range of 1.0 to 14.0.

In view of further improving the effect of the present invention, the pHof the composition is preferably 3.0 to 12.5, more preferably 3.0 to9.0, and even more preferably 4.0 to 8.0.

In the present specification, the pH of the composition is determined bymeasuring pH at 25° C. by using a pH meter (F-51 (trade name)manufactured by HORIBA, Ltd.).

Container

The composition can be stored, transported, and used by being filledinto any container.

It is preferable to use a container that has a high degree ofcleanliness and is unlikely to cause elution of impurities. Examples ofthe container to be filled with the composition include a “CLEAN BOTTLE”series manufactured by AICELLO CORPORATION, and “PURE BOTTLE”manufactured by KODAMA PLASTICS Co., Ltd.

Manufacturing Method

The manufacturing method of the composition is not particularly limited.For example, by mixing together the components described above, thecomposition can be manufactured. There is no particular limitation onthe order and/or timing of mixing together the components describedabove. Examples of the manufacturing method of the composition include amethod of sequentially adding an iodic acid compound, the specificcompound, and necessary optional components to a stirrer of a mixerfilled with purified pure water and then thoroughly stirring thecomponents so that the components are mixed together.

Examples of the manufacturing method of the composition include a methodof adjusting the pH of the washing solution in advance by using a pHadjuster and then mixing together components and a method of mixingtogether components and then adjusting the pH to a preset value by usinga pH adjuster.

Furthermore, the composition may be manufactured by a method ofmanufacturing a concentrated solution having a lower water content thanthe water content of the composition to be used, and diluting thesolution with a diluent (preferably water) when the composition needs tobe used so that the content of each component is adjusted to apredetermined content. The composition may also be manufactured by amethod of diluting the concentrated solution with a diluent and thenadjusting the pH thereof to a preset value by using a pH adjuster. Fordiluting the concentrated solution, a predetermined amount of diluentmay be added to the concentrated solution or a predetermined amount ofconcentrated solution may be added to a diluent.

Object to be Treated

The composition is used for removing a transition metal-containingsubstance (particularly, a Ru-containing substance) on a substrate.

In the present specification, “on a substrate” includes, for example,all of the front and back, the lateral surfaces, and the inside ofgrooves of a substrate, and the like. The transition metal-containingsubstance on a substrate includes not only a transition metal-containingsubstance which directly contacts the surface of the substrate but alsoa transition metal-containing substance which is on the substratethrough another layer.

The transition metal-containing substance is not particularly limited aslong as it is a substance containing a transition metal (a transitionmetal atom).

Examples of the transition metal include a metal M selected from Ru(ruthenium), Rh (rhodium), Ti (titanium), Ta (tantalum), Co (cobalt), Cr(chromium), Hf (hafnium), Os (osmium), and Pt (platinum), Ni (nickel),Mn (manganese), Cu (copper), Zr (zirconium), Mo (molybdenum), La(lanthanum), W (tungsten), and Ir (iridium).

Among the above, a ruthenium (Ru)-containing substance is preferable asthe transition metal-containing substance.

The content of Ru atoms in the Ru-containing substance with respect tothe total mass of the Ru-containing substance is preferably equal to orhigher than 10% by mass, more preferably equal to or higher than 30% bymass, even more preferably equal to or higher than 50% by mass, andparticularly preferably equal to or higher than 90% by mass. The upperlimit thereof is not particularly limited, but is preferably 100% bymass or less with respect to the total mass of the Ru-containingsubstance.

The Ru-containing substance is not particularly limited as long as it isa substance containing Ru (a Ru atom). Examples of the Ru-containingsubstance include simple Ru, an Ru-containing alloy, an oxide of Ru, anitride of Ru, and an oxynitride of Ru.

The oxide, nitride, and oxynitride described above may be a compositeoxide, a composite nitride, and a composite oxynitride containing Ru.

The object to be treated is a substrate having a transitionmetal-containing substance (particularly, a Ru-containing substance).

That is, the object to be treated includes at least a substrate and atransition metal-containing substance (particularly, a Ru-containingsubstance) on the substrate.

The type of substrate is not particularly limited, but is preferably asemiconductor substrate.

Examples of the substrate include a semiconductor wafer, a glasssubstrate for a photomask, a glass substrate for liquid crystal display,a glass substrate for plasma display, a substrate for field emissiondisplay (FED), a substrate for an optical disk, a substrate for amagnetic disk, and a substrate for a magneto-optical disk.

Examples of materials constituting the semiconductor substrate includesilicon, silicon germanium, a Group III-V compound such as GaAs, and acombination of these.

The use of the object to be treated having been treated with thecomposition according to the embodiment of the present invention is notparticularly limited. For example, such an object to be treated may beused for dynamic random access memory (DRAM), ferroelectric randomaccess memory (FRAM (registered trademark)), magnetoresistive randomaccess memory (MRAM), and phase change random access memory (PRAM), ormay be used for a logic circuit, a processor, and the like.

The form of the transition metal-containing substance (particularly, theRu-containing substance) on the substrate is not particularly limited.For example, the Ru-containing substance may be disposed in the form ofa film (particularly, a Ru-containing film), in the form of a wiringline (particularly, a Ru-containing wiring line), or in the form ofparticles.

As described above, the transition metal preferably includes Ru, and theobject to be treated is preferably an object to be treated including asubstrate and a Ru-containing film, a Ru-containing wiring line, or aparticle-like Ru-containing substance which is disposed on thesubstrate.

Examples of the substrate, on which the Ru-containing substance isdisposed in the form of particles, include a substrate obtained byperforming dry etching on a substrate on which a Ru-containing film isdisposed such that particle-like Ru-containing substances are thenattached to the substrate as residues as will be described later, and asubstrate obtained by performing a chemical mechanical polishing (CMP)treatment on the Ru-containing film such that particle-likeRu-containing substances are then attached to the substrate as residuesas will be described later.

The thickness of the Ru-containing film is not particularly limited, andmay be appropriately selected according to the use. For example, thethickness is preferably 200 nm or less, more preferably 100 nm or less,and even more preferably 50 nm or less. The lower limit thereof is notparticularly limited, and is preferably 0.1 nm or more.

The Ru-containing film may be disposed only on one of the main surfacesof the substrate, or may be disposed on both the main surfaces of thesubstrate. Furthermore, the Ru-containing film may be disposed on theentire main surface of the substrate, or may be disposed on a portion ofthe main surface of the substrate.

The object to be treated may include various layers and/or structures asdesired, in addition to the transition metal-containing substanceparticularly, the Ru-containing substance). For example, a metal wire, agate electrode, a source electrode, a drain electrode, an insulatinglayer, a ferromagnetic layer, and/or a non-magnetic layer, and the likemay be disposed on the substrate.

The substrate may include an exposed integrated circuit structure.Examples of the integrated circuit structure include an interconnectionmechanism such as a metal wire and a dielectric material. Examples ofmetals and alloys used for the interconnection mechanism includealuminum, a copper-aluminum alloy, copper, titanium, tantalum, cobalt,silicon, titanium nitride, tantalum nitride, and tungsten. The substratemay include a layer of silicon oxide, silicon nitride, silicon carbide,and/or carbon-doped silicon oxide.

The size, thickness, shape, layer structure, and the like of thesubstrate are not particularly limited, and can be appropriatelyselected as desired.

Manufacturing Method of Object to be Treated

The manufacturing method of the object to be treated is not particularlylimited, and known manufacturing methods can be used.

For example, by using a sputtering method, a chemical vapor deposition(CVD) method, a molecular beam epitaxy (MBE) method, or an atomic layerdeposition (ALD) as the manufacturing method of the object to betreated, it is possible to form a transition metal-containing film(particularly, a Ru-containing film) on a substrate. In a case where atransition metal-containing film (particularly, a Ru-containing film) isformed by a sputtering method or a CVD method, sometimes the transitionmetal-containing film (particularly, the Ru-containing film) adheres tothe back surface of the substrate (a surface on the side opposite to theside of the transition metal-containing film (particularly, theRu-containing film)) on which the transition metal-containing film(particularly, the Ru-containing film) is disposed.

Furthermore, the above method may be performed via a predetermined masksuch that a transition metal-containing wiring line (particularly, aRu-containing wiring line) is formed on a substrate.

In addition, a predetermined treatment may be performed on a substrateon which a transition metal-containing film (particularly, aRu-containing film) or a transition metal-containing wiring line(particularly, a Ru-containing wiring line) is disposed, such that thesubstrate is used as an object to be treated by the treatment methodaccording to an embodiment of the present invention.

For example, a substrate on which a transition metal-containing film(particularly, a Ru-containing film) or a transition metal-containingwiring line (particularly, a Ru-containing wiring line) is disposed maybe subjected to dry etching such that a substrate having dry etchingresidues containing a transition metal (particularly, Ru) ismanufactured. Furthermore, a substrate on which a transitionmetal-containing film (particularly, a Ru-containing film) or atransition metal-containing wiring line (particularly, a Ru-containingwiring line) is disposed may be subjected to CMP such that a substratehaving a transition metal-containing substance (particularly, aRu-containing substance) is manufactured.

Method for Treating Substrate

The method for treating a substrate according to an embodiment of thepresent invention (hereinafter, also called “present treatment method”)includes a step A of removing a transition metal-containing substance(particularly, a Ru-containing substance) on a substrate by using thecomposition described above.

In addition, the substrate on which a transition metal-containingsubstance (particularly, a Ru-containing substance) is disposed, whichis an object to be treated by the present treatment method, is asdescribed above.

Examples of the specific method of the step A include a method ofbringing an object to be treated, a substrate on which a transitionmetal-containing substance (particularly, a Ru-containing substance) isdisposed, into contact with the composition.

The method of bringing the substrate into contact with the compositionis not particularly limited, and examples thereof include a method ofimmersing the object to be treated in the composition put in a tank, amethod of spraying the composition onto the object to be treated, amethod of causing the composition to flow on the object to be treated,and a combination of these. Among these, the method of immersing theobject to be treated in the composition is preferable.

In order to further enhance the washing ability of the composition, amechanical stirring method may also be used.

Examples of the mechanical stirring method include a method ofcirculating the composition on an object to be treated, a method ofirrigating an object to be treated with the composition or spraying thecomposition onto an object to be treated, and a method of stirring thecomposition by using ultrasonic or megasonic waves.

The treatment time of the step A can be appropriately adjusted. Thetreatment time (the contact time between the composition and the objectto be treated) is not particularly limited, and is preferably 0.25 to 10minutes, and more preferably 0.5 to 2 minutes.

The temperature of the composition during the treatment is notparticularly limited, but is preferably 20° C. to 75° C., morepreferably 20° C. to 65° C., even more preferably 40° C. to 65° C., andparticularly preferably 50° C. to 65° C.

In the step A, a treatment may be performed in which while theconcentration of the iodic acid compound and/or the specific compound inthe composition is being measured, a solvent (preferably water) is addedto the composition as necessary. In a case where this treatment isperformed, the concentration of components in the composition can bestably maintained in a predetermined range.

Specifically, examples of suitable embodiments of the step A include astep A1 of performing a recess etching treatment on a Ru-containingwiring line disposed on a substrate by using the composition, a step A2of removing a Ru-containing film on an outer edge portion of asubstrate, on which the Ru-containing film is disposed, by using thecomposition, a step A3 of removing a Ru-containing substance attached toa back surface of a substrate, on which a Ru-containing film isdisposed, by using the composition, a step A4 of removing aRu-containing substance on a substrate, which has undergone dry etching,by using the composition, and a step A5 of removing a Ru-containingsubstance on a substrate, which has undergone a chemical mechanicalpolishing treatment, by using the composition.

As the step A, among the above, the step A2 or the step A3 ispreferable.

Hereinafter, the present treatment method used in each of the abovetreatments will be described.

Step A1

Examples of the step A include a step A1 of performing a recess etchingtreatment by using the composition on a Ru-containing wiring linedisposed on a substrate.

FIG. 1 is a schematic cross-sectional top view showing an example of asubstrate having a Ru-containing wiring line (hereinafter, also called“wiring board”) which is an object to be treated by the recess etchingtreatment in the step A1.

A wiring board 10 a shown in FIG. 1 has a substrate not shown in thedrawing, an insulating film 12 having a groove disposed on thesubstrate, a barrier metal layer 14 disposed along the interior wall ofthe groove, and a Ru-containing wiring line 16 that fills up the insideof the groove.

The substrate and the Ru-containing wiring line in the wiring board areas described above.

It is preferable that the Ru-containing wiring line contain simple Ru,an alloy of Ru, an oxide of Ru, a nitride of Ru, or an oxynitride of Ru.

The material constituting the barrier metal layer in the wiring board isnot particularly limited, and examples thereof include TiN and TaN.

In FIG. 1 , an embodiment is illustrated in which the wiring board has abarrier metal layer. However, the wiring board may not have the barriermetal layer.

The method for manufacturing the wiring board is not particularlylimited, and examples thereof include a method having a step of formingan insulating film on a substrate, a step of forming a groove in theinsulating film, a step of forming a barrier metal layer on theinsulating film, a step of forming a Ru-containing film that fills upthe groove, and a step of performing a smoothing treatment on theRu-containing film.

In the step A1, by performing a recess etching treatment on theRu-containing wiring line in the wiring board by using theaforementioned composition, a portion of the Ru-containing wiring linecan be removed, and a recess can be formed.

More specifically, in a case where the step A1 is performed, as shown inthe wiring board 10 b in FIG. 2 , a portion of the barrier metal layer14 and the Ru-containing wiring line 16 is removed, and a recess 18 isformed.

Examples of specific methods of the step A1 include a method of bringingthe wiring board into contact with the composition.

The method of bringing the wiring board into contact with thecomposition is as described above.

The suitable ranges of the contact time between the chemical liquid andthe wiring board and the temperature of the chemical liquid are asdescribed above.

Step B

Before or after the step A1, as necessary, a step B of treating thesubstrate obtained by the step A1 by using a predetermined solution(hereinafter, also called “specific solution”) may be performed.

Particularly, as described above, in a case where the barrier metallayer is disposed on the substrate, the solubility in the compositionaccording to the embodiment of the present invention varies between thecomponent constituting the Ru-containing wiring line and the componentconstituting the barrier metal layer depending on the type ofcomponents. In this case, it is preferable to adjust the degree ofsolubility of the Ru-containing wiring line and the barrier metal layerby using a solution that exhibits a higher dissolving ability to thebarrier metal layer.

In this respect, as the specific solution, a solution is preferablewhich exhibits a poor dissolving ability to the Ru-containing wiringline but exhibits an excellent dissolving ability to the substanceconstituting the barrier metal layer.

Examples of the specific solution include a solution selected from thegroup consisting of a mixed solution of hydrofluoric acid and hydrogenperoxide water (FPM), a mixed solution of sulfuric acid and hydrogenperoxide water (SPM), a mixed solution of aqueous ammonia and hydrogenperoxide water (APM), and a mixed solution of hydrochloric acid andhydrogen peroxide water (HPM).

The composition of FPM is, for example, preferably in a range of“hydrofluoric acid:hydrogen peroxide water:water = 1:1:1” to“hydrofluoric acid:hydrogen peroxide water:water = 1:1:200” (volumeratio).

The composition of SPM is, for example, preferably in a range of“sulfuric acid:hydrogen peroxide water:water = 3:1:0” to “sulfuricacid:hydrogen peroxide water:water = 1:1:10” (volume ratio).

The composition of APM is, for example, preferably in a range of“aqueous ammonia:hydrogen peroxide water:water = 1:1:1” to “aqueousammonia:hydrogen peroxide water:water = 1:1:30” (volume ratio).

The composition of HPM is, for example, preferably in a range of“hydrochloric acid:hydrogen peroxide water:water = 1:1:1” to“hydrochloric acid:hydrogen peroxide water:water = 1:1:30” (volumeratio).

The preferred compositional ratio described above means a compositionalratio determined in a case where the hydrofluoric acid is 49% by masshydrofluoric acid, the sulfuric acid is 98% by mass sulfuric acid, theaqueous ammonia is 28% by mass aqueous ammonia, the hydrochloric acid is37% by mass hydrochloric acid, and the hydrogen peroxide water is 31% bymass hydrogen peroxide water.

Among these, as the specific solution, in view of dissolving ability forthe barrier metal layer, SPM, APM, or HPM is preferable.

As the specific solution, in view of reducing roughness, APM, HPM, orFPM is preferable, and APM is more preferable.

As the specific solution, in view of excellent performance balance, APMor HPM is preferable.

In the step B, as the method of treating the substrate obtained by thestep A1 by using the specific solution, a method of bringing thesubstrate obtained by the step A1 into contact with the specificsolution is preferable.

The method of bringing the substrate obtained by the step A1 intocontact with the specific solution is not particularly limited, andexamples thereof include the same method as the method of bringing thesubstrate into contact with the composition.

The contact time between the specific solution and the substrateobtained by the step A1 is, for example, preferably 0.25 to 10 minutes,and more preferably 0.5 to 5 minutes.

In the present treatment method, the step A1 and the step B may bealternately repeated.

In a case where the steps are alternately repeated, it is preferablethat each of the step A1 and the step B be performed 1 to 10 times.Furthermore, in a case where the step A1 and the step B are alternatelyrepeated, the step performed firstly and the step performed lastly maybe any of the step A1 or the step B.

Step A2

Examples of the step A include a step A2 of removing a Ru-containingfilm at the outer edge of a substrate, on which the Ru-containing filmis disposed, by using the composition.

FIG. 3 is a schematic view (top view) showing an example of a substrate,on which a Ru-containing film is disposed, as an object to be treated bythe step A2.

An object 20 to be treated by the step A2 shown in FIG. 3 is a laminatehaving a substrate 22 and a Ru-containing film 24 disposed on one mainsurface (entire region surrounded by the solid line) of the substrate22. As will be described later, in step A2, the Ru-containing film 24positioned at an outer edge 26 (the region outside the broken line) ofthe object 20 to be treated is removed.

The substrate and the Ru-containing film in the object to be treated areas described above.

It is preferable that the Ru-containing film contain simple Ru, an alloyof Ru, an oxide of Ru, a nitride of Ru, or an oxynitride of Ru.

The specific method of the step A2 is not particularly limited, andexamples thereof include a method of supplying the composition from anozzle such that the composition comes into contact with only theRu-containing film as a removal target at the outer edge portion of thesubstrate.

At the time of performing the treatment of the step A2, it is possibleto preferably use the substrate treatment device and the substratetreatment method described in JP2010-267690A, JP2008-080288A,JP2006-100368A, and JP2002-299305A.

The method of bringing the object to be treated into contact with thecomposition is as described above.

The suitable ranges of the contact time between the composition and theobject to be treated and the temperature of the composition are asdescribed above.

Step A3

Examples of the step A include a step A3 of removing a Ru-containingsubstance attached to the back surface of a substrate, on which aRu-containing film is disposed, by using the composition.

Examples of the object to be treated by the step A3 include the objectto be treated used in the step A2. At the time of forming the object tobe treated includes a Ru-containing film disposed on one main surface ofthe substrate, used in the step A2, the Ru-containing film is formed bysputtering, CVD, or the like. At this time, sometimes a Ru-containingsubstance is attached to a surface (back surface) of the substrate thatis opposite to the Ru-containing film. The step A3 is performed toremove such a Ru-containing substance in the object to be treated.

The specific method of the step A3 is not particularly limited, andexamples thereof include a method of spraying the composition such thatthe composition comes into contact with only the back surface of thesubstrate.

The method of bringing the object to be treated into contact with thecomposition is as described above.

The suitable ranges of the contact time between the composition and theobject to be treated and the temperature of the composition are asdescribed above.

Step A4

Examples of the step A include a step A4 of removing a Ru-containingsubstance on a substrate, which has undergone dry etching, by using thecomposition.

FIG. 4 is a schematic view showing an example of the object to betreated by the step A4.

An object 30 to be treated shown in FIG. 4 comprises a Ru-containingfilm 34, an etching stop layer 36, an interlayer insulating film 38, anda metal hard mask 40 in this order on a substrate 32. Through a dryetching process or the like, a hole 42 exposing the Ru-containing film34 is formed at a predetermined position. That is, the object to betreated shown in FIG. 4 is a laminate which comprises the substrate 32,the Ru-containing film 34, the etching stop layer 36, the interlayerinsulating film 38, and the metal hard mask 40 in this order andcomprises the hole 42 that extends from the surface of the metal hardmask 40 to the surface of the Ru-containing film 34 at the position ofthe opening portion of the metal hard mask 40. An interior wall 44 ofthe hole 42 is constituted with a cross-sectional wall 44 a whichincludes the etching stop layer 36, the interlayer insulating film 38,and the metal hard mask 40, and a bottom wall 44 b which includes theexposed Ru-containing film 34. A dry etching residue 46 is attached tothe interior wall 44.

The dry etching residue includes a Ru-containing substance.

It is preferable that the Ru-containing film contain simple Ru, an alloyof Ru, an oxide of Ru, a nitride of Ru, or an oxynitride of Ru.

It is preferable that the Ru-containing substance contain simple Ru, analloy of Ru, an oxide of Ru, a nitride of Ru, or an oxynitride of Ru.

As the interlayer insulating film and the metal hard mask, knownmaterials are selected.

Although FIG. 4 describes an embodiment in which a metal hard mask isused, a resist mask formed of a known photoresist material may also beused.

Examples of the specific method of the step A4 include a method ofbringing the aforementioned object to be treated into contact with thecomposition.

The method of bringing the wiring board into contact with thecomposition is as described above.

The suitable ranges of the contact time between the chemical liquid andthe wiring board and the temperature of the chemical liquid are asdescribed above.

Step A5

Examples of the step A include a step A5 of removing a Ru-containingsubstance on a substrate, which has undergone a chemical mechanicalpolishing (CMP) treatment, by using the composition.

The CMP technique is used for smoothing an insulating film, smoothingconnection holes, and a process of manufacturing damascene wiring lineand the like. In some cases, a substrate having undergone CMP iscontaminated with a large amount of particles used as abrasiveparticles, metal impurities, and the like. Therefore, it is necessary toremove these contaminants and wash the substrate before the nextprocessing stage starts. In a case where the object to be treated by CMPhas a Ru-containing wiring line and the step A5 is performed, it ispossible to remove a Ru-containing substance which is generated in acase where the object to be treated by CMP includes a Ru-containingwiring line or a Ru-containing film and attached onto the substrate.

As described above, examples of the object to be treated by the step A5include a substrate having undergone CMP that has a Ru-containingsubstance.

It is preferable that the Ru-containing substance contain simple Ru, analloy of Ru, an oxide of Ru, a nitride of Ru, or an oxynitride of Ru.

Examples of the specific method of the step A5 include a method ofbringing the aforementioned object to be treated into contact with thecomposition.

The method of bringing the wiring board into contact with thecomposition is as described above.

The suitable ranges of the contact time between the chemical liquid andthe wiring board and the temperature of the chemical liquid are asdescribed above.

Step C

As necessary, the present treatment step may have a step C of performinga rinsing treatment on the substrate obtained by the step A by using arinsing liquid after the step A.

As the rinsing liquid, for example, hydrofluoric acid (preferably 0.001%to 1% by mass hydrofluoric acid), hydrochloric acid (preferably 0.001%to 1% by mass hydrochloric acid), hydrogen peroxide water (preferably0.5% to 31% by mass hydrogen peroxide water, and more preferably 3% to15% by mass hydrogen peroxide water), a mixed solution of hydrofluoricacid and hydrogen peroxide water (FPM), a mixed solution of sulfuricacid and hydrogen peroxide water (SPM), a mixed solution of aqueousammonia and hydrogen peroxide water (APM), a mixed solution ofhydrochloric acid and hydrogen peroxide water (HPM), aqueous carbondioxide (preferably 10 to 60 ppm by mass aqueous carbon dioxide),aqueous ozone (preferably 10 to 60 ppm by mass aqueous ozone), aqueoushydrogen (preferably 10 to 20 ppm by mass aqueous hydrogen), an aqueouscitric acid solution (preferably a 0.01% to 10% by mass aqueous citricacid solution), acetic acid (preferably an undiluted acetic acidsolution or a 0.01% to 10% by mass aqueous acetic acid solution),sulfuric acid (preferably a 1% to 10% by mass aqueous sulfuric acidsolution), aqueous ammonia (preferably 0.01% to 10% by mass aqueousammonia), isopropyl alcohol (IPA), an aqueous hypochlorous acid solution(preferably a 1% to 10% by mass aqueous hypochlorous acid solution),aqua regia (preferably aqua regia obtained by mixing together “37% bymass hydrochloric acid:60% by mass nitric acid” at a volume ratio of“2.6:1.4” to “3.4:0.6”), ultrapure water, nitric acid (preferably 0.001%to 1% by mass nitric acid), perchloric acid (preferably 0.001% to 1% bymass perchloric acid), an aqueous oxalic acid solution (preferably a0.01% to 10% by mass aqueous oxalic acid solution), or an aqueousperiodic acid solution (preferably a 0.5% to 10% by mass aqueousperiodic acid solution, examples of the periodic acid includeorthoperiodic acid and metaperiodic acid) is preferable.

The content of each specific example additionally described in eachspecific example of the rinsing liquid is a content with respect to thetotal mass of the rinsing liquid.

The preferred conditions required to FPM, SPM, APM, and HPM are the sameas the suitable aspects of, for example, to FPM, SPM, APM, and HPM usedas the specific solution described above.

The hydrofluoric acid, nitric acid, perchloric acid, and hydrochloricacid mean aqueous solutions obtained by dissolving HF, HNO₃, HClO₄, andHCl in water respectively.

The ozonated water, aqueous carbon dioxide, and aqueous hydrogen meanaqueous solutions obtained by dissolving O₃, CO₂, and H₂ in waterrespectively.

As long as the purpose of the rinsing step is not impaired, theserinsing liquids may be used by being mixed together.

Among the above, as the rinsing liquid, in view of further reducingchlorine remaining on the surface of the substrate after the rinsingstep, aqueous carbon dioxide, aqueous ozone, aqueous hydrogen,hydrofluoric acid, an aqueous citric acid solution, hydrochloric acid,sulfuric acid, aqueous ammonia, hydrogen peroxide water, SPM, APM, HPM,IPA, an aqueous hypochlorous acid solution, aqua regia, or FPM ispreferable, and hydrofluoric acid, hydrochloric acid, hydrogen peroxidewater, SPM, APM, HPM, or FPM is more preferable.

Examples of the specific method of the step C include a method ofbringing the substrate as an object to be treated obtained by the step Ainto contact with the rinsing liquid.

The method of bringing the substrate into contact with the rinsingliquid is performed by immersing the substrate in the rinsing liquid putin a tank, spraying the rinsing liquid on the substrate, causing therinsing liquid to flow on the substrate, or a method composed of an anycombination of these.

The treatment time (contact time between the rinsing liquid and theobject to be treated) is not particularly limited, but is 5 seconds to 5minutes for example.

The temperature of the rinsing liquid during the treatment is notparticularly limited. Generally, the temperature of the rinsing liquidis preferably 16° C. to 60° C., and more preferably 18° C. to 40° C. Ina case where SPM is used as the rinsing liquid, the temperature thereofis preferably 90° C. to 250° C.

As necessary, the present treatment method may have a step D ofperforming a drying treatment after the step C. The method of the dryingtreatment is not particularly limited, and examples thereof include spindrying, causing a drying gas to flow on the substrate, heating thesubstrate by a heating unit (for example, a hot plate or an infraredlamp), isopropyl alcohol (IPA) vapor drying, Marangoni drying, Rotagonidrying, and any combination of these.

The drying time can be appropriately changed depending on the specificmethod to be used. For example, the drying time is about 30 seconds to afew minutes.

Step D

As necessary, the present treatment method may have a step D ofperforming a drying treatment after the step C.

The method of the drying treatment is not particularly limited, andexamples thereof include spin drying, placing the substrate under adrying gas stream, heating the substrate by a heating unit (for example,a hot plate or an infrared lamp), isopropyl alcohol (IPA) vapor drying,Marangoni drying, Rotagoni drying, and a combination of these.

The drying time can be appropriately changed depending on the specificmethod to be used. For example, the drying time is about 30 seconds to afew minutes.

Other Steps

The present treatment method may be performed in combination before orafter other steps performed on a substrate. While being performed, thepresent treatment method may be incorporated into those other steps.Alternatively, while those other steps are being performed, thetreatment method according to the embodiment of the present inventionmay be incorporated into the steps and performed.

Examples of those other steps include a step of forming each structuresuch as a metal wire, a gate structure, a source structure, a drainstructure, an insulating layer, a ferromagnetic layer, and/or anon-magnetic layer (for example, layer formation, etching, chemicalmechanical polishing, modification, and the like), a step of formingresist, an exposure step and a removing step, a heat treatment step, awashing step, and an inspection step.

The present treatment method may be performed at any stage among theback-end process (BEOL: back end of the line), the middle process (MOL:middle of the line), and the front-end process (FEOL: front end of theline). It is preferable that the present treatment method be performedin a front-end process or a middle process.

EXAMPLES

Hereinafter, the present invention will be more specifically describedbased on examples. The materials, the amounts and ratios of thematerials used, the details of treatments, and the procedures oftreatments shown in the following examples can be appropriately changedas long as the gist of the present invention is maintained. Therefore,the scope of the present invention is not restricted by the followingexamples.

Preparation of Composition

The compositions having the makeups shown in the following Table 1 wereprepared, and the prepared compositions were tested as below.

All of the following components used for preparing the compositions areproducts obtained from the market, and include the products classifiedas a semiconductor grade or products classified as a high-purity grade.

Iodic Acid Compound

-   Orthoperiodic acid-   Metaperiodic acid-   Iodic acid

Specific Compound

-   D-1: ethyltrimethylammonium hydroxide-   D-2: ethyltrimethylammonium chloride-   D-3: ethyltrimethylammonium bromide-   D-4: ethyltrimethylammonium fluoride-   E-1: diethyldimethylammonium hydroxide-   E-2: diethyldimethylammonium chloride-   F-1: methyltriethylammonium hydroxide-   F-2: methyltriethylammonium chloride-   G-1: trimethyl(hydroxyethyl)ammonium hydroxide-   H-1: methyltributylammonium hydroxide-   1-1: dimethyldipropylammonium hydroxide-   J-1: benzyltrimethylammonium hydroxide-   K-1: benzyltriethylammonium hydroxide-   L-1: triethyl(hydroxyethyl)ammonium hydroxide-   M-1: dodecyltrimethylammonium hydroxide-   N-1: tetradecyltrimethylammonium hydroxide-   O-1: hexadecyltrimethylammonium hydroxide

Compound for Comparison

-   A-2: tetramethylammonium chloride-   B-1: tetraethylammonium hydroxide

Water

-   Ultrapure water

Examples and Comparative Examples

Orthoperiodic acid, the specific compound, and a chloride ion at thecontents described in the following table were added to ultrapure water,thereby preparing a mixed solution. Then, the mixed solution wasthoroughly stirred with a stirrer, thereby obtaining a composition ofExample 1.

Compositions of examples and comparative examples other than Example 1were prepared in the same procedure as in Example 1, except that eachcomponent and the like were changed according to the following tables.

The chloride ion concentration in the composition having a low chlorideion concentration was measured using a concentrator column, asnecessary. The chloride ion contained in the composition is derived froman anion of the specific compound and from an impurity mixed in thesynthesis process of the specific compound.

Test Ru Dissolving Ability

Substrates were prepared in which a Ru layer (layer composed of simpleRu) was formed on one surface of a commercial silicon wafer (diameter:12 inches) by a PVD method.

Each of the obtained substrates was put in a container filled with thecomposition of each of the examples or comparative examples, and thecomposition was stirred to perform a Ru layer removal treatment for 1minute. The temperature of the composition was 25° C.

The thicknesses of the Ru layers before and after the treatment weremeasured with an X-ray fluorescence analyzer for thin film evaluation(XRF AZX-400, manufactured by Rigaku Corporation). From the differencebetween the thickness of the Ru layer before the treatment and thethickness of the Ru layer after the treatment, an etching rate (Ålmin)of the Ry layer was calculated. The calculated etching rate of the Rulayer was evaluated according to the following evaluation standard.

Evaluation Standard

-   5: The etching rate is 250 Å/min or more.-   4: The etching rate is 200 Å/min or more and less than 250 Å/min.-   3: The etching rate is 150 Å/min or more and less than 200 Å/min.-   2: The etching rate is 100 Å/min or more and less than 150 Å/min.-   1: The etching rate is less than 100 Å/min.

Metal Residue Removability

By using a total reflection X-ray fluorescence analyzer (TXRF-V310,manufactured by Rigaku Corporation), the amount of metal residues (metalresidues other than Ru constituting the Ru layer) on the substratesurface after the <Ru dissolving ability> described above wasquantified. The amount of metal residues before the treatment with thecomposition and the amount of metal residues after the treatment withthe composition are compared with each other, proportion of metalresidue (%) = 100 x [amount of metal residues after treatment(atoms/cm²)]/[amount of metal residues before treatment (atoms/cm²)] wascalculated, and the metal residue removability was evaluated accordingto the following evaluation standard.

Evaluation Standard

-   5: The proportion of metal residue is 25% or less.-   4: The proportion of metal residue is more than 25% and 50% or less.-   3: The proportion of metal residue is more than 50% and 75% or less.-   2: The proportion of metal residue is more than 75% and 85% or less.-   1: The proportion of metal residue is more than 85%.

The evaluation results are shown in Tables 1 and 2.

Each description in the tables is as follows.

“Total number of carbon atoms” in the column of “Specific compound”means the sum of the number of carbon atoms that the specific compoundhas (total number of carbon atoms in R¹ to R⁴ in Formula (1)).

The column of “(A)/(B)” shows the mass ratio of the content of the iodicacid compound to the content of the chloride ion.

The column of “pH” shows a pH measured in a composition at 25° C. byusing a known pH meter by a method based on JIS Z8802-1984.

“Remainder” in the column of “Water” means that the remainder other thanthe iodic acid compound, the specific compound, and the chloride ioncontained in the composition is water.

TABLE 1 Component Evaluation result [A] lodic acid compound Specificcompound (B) Chloride ion (A)(B) pH Water Type Content [% by mass] TypeContent [% by mass] Total number of carbon atoms Content [ppum by mass]Ru dissolving ability Metal residue removability Example 1 Orthopedicacid 1.50 D-1 0.70 5 0.39 1.7 × 10′ 6.5 Reminder 5 5 Example 2Orthoepedic acid 0.50 E-1 0.10 6 0.01 5.0 × 10′ 7.8 Reminder 5 5 Example3 Metaperiodic acid 1.00 F-1 0.20 7 0.82 5.0 × 10′ 6.5 Reminder 5 5Example 4 Metaperiodic acid 2.00 G-1 0.50 5 0.001 2.0 × 10′ 4.5 Reminder5 5 Example 5 Metaperiodic acid 0.10 E-1 0.001 6 - - 4.2 Reminder 4 1Example 6 Orthopedic acid 1.00 H-1 0.08 13 0.006 1.7 × 10′ 4.2 Reminder4 5 Example 7 Orthopedic acid 1.00 I-1 0.10 8 0.06 1.7 × 10′ 5.5Reminder 4 5 Example 8 Metaperiodic acid 1.00 J-1 0.22 10 0.009 1.1 ×10′ 6.2 Reminder 4 5 Example 9 Metaperiodic acid 1.00 K-1 0.35 13 0.052.0 × 10′ 7.4 Reminder 4 5 Example 10 Orthopedic acid 1.00 L-1 0.05 80.001 1.0 × 10′ 4.3 Reminder 4 5 Example 11 Orthopedic acid 1.00 M-10.25 15 0.08 1.3 × 10′ 5.7 Reminder 5 5; Example 12 Orthopedic acid 1.00N-1 0.30 16 0.01 1.0 × 10′ 6.0 Reminder 2 5 Example 13 Orthopedic acid0.50 D-2 0.10 5 3000 1.7 5.3 Reminder 5 3 Example 14 Orthpedic acid 0.50D-3 0.20 5 0.005 1.0 × 10′ 6.8 Reminder 4 5 Example 15 Orthopedic acid0.50 D-4 0.08 5 0.02 2.5 × 10′ 4.0 Reminder 4 5 Example 16 lodic acid0.10 D-1 0.04 5 0.03 1.3 × 10′ 6.5 Reminder 3 5 Example 17 lodic acid0.10 E-1 0.05 6 0.07 1.4 × 10′ 7.5 Reminder 3 5 Example 18 Orthopedicacid 1.20 E-1 0.01 6 0.1 1.2 × 10′ 8.8 Reminder 4 3 Example 19Orthopedic acid 0.60 F-1 0.30 7 0.05 1.2 × 10′ 8.1 Reminder 4 3 Example20 Orthopedic acid 0.90 F-1 0.55 7 0.09 1.0 × 10′ 8.9 Reminder 4 3Example 21 Orthopedic acid 1.00 E-1 0.55 6 0.05 1.6 × 10′ 9.6 Reminder 35 Example 22 Orthoperiodic acid 1.50 P-1 1.00 7 0.02 7.5 × 10⁵ 10.5Remainder 3 5 Example 23 Orthoperiodic acid 1.00 Q-1 0.78 5 0.03 3.3 ×10⁵ 12.1 Remainder 3 5 Example 24 Orthoperiodic acid 1.00 P-1 0.005 70.1 1.0 × 10⁵ 1.2 Remainder 2 5 Example 25 Orthoperiodic acid 1.00 E-10.009 6 0.05 2.0 × 10⁵ 2.0 Remainder 2 5 Example 26 Orthoperiodic acid0.30 D-2 0.12 5 2500 1.2 6.0 Remainder 5 3 Example 27 Orthoperiodic acid2.00 F-2 0.75 7 8000 2.5 6.5 Remainder 4 2 Example 28 Orthoperiodic acid0.30 D-1 0.002 5 0.0001 3.0 × 10⁷ 4.2 Remainder 4 3 Example 29Orthoperiodic acid 0.00006 D-1 0.006 5 0.0009 6.6 × 10² 6.0 Remainder 32 Example 30 Orthoperiodic acid 0.06 E-2 0.001 6 120 5.0 5.5 Remainder 43 Example 31 Orthoperiodic acid 0.01 E-1 0.002 6 0.0001 1.0 × 10⁶ 6.4Remainder 4 3 Example 32 Orthoperiodic acid 0.001 E-2 0.001 6 20 0.5 7.4Remainder 3 3 Example 33 Orthoperiodic acid 4.00 G-1 1.20 5 0.1 4.0 ×10³ 7.5 Remainder 4 5 Example 34 Orthoperiodic acid 6.50 F-1 1.00 7 0.041.6 × 10⁶ 3.7 Remainder 3 5 Example 35 Orthoperiodic acid 0.01 E-10.0005 6 - - 5.5 Remainder 2 1 Example 36 Orthoperiodic acid 3.50 F-12.00 7 0.5 7.0 × 10⁴ 8.8 Remainder 3 4 Example 37 Orthoperiodic acid2.00 D-1 0.01 5 0.3 6.7 × 10⁴ 4.2 Remainder 5 4 Example 38 Metaperiodicacid 1.00 0-1 0.7 19 0.05 2.0 × 10⁵ 65 Remainder 2 5 Comparative Example1 Orthoperiodic acid 2.00 A-2 0.20 4 0.1 - 4.0 Remainder 1 4 ComparativeExample 2 Orthoperiodic acid 1.00 B-1 0.10 8 0.02 - 65 Remainder 1 4Comparative Example 3 - - D-1 1.00 5 0.08 - 8.0 Remainder 1 4Comparative Example 4 Metaperiodic acid 0.50 - - - - - 1.5 Remainder 1 1

From the results shown in the tables, it has been confirmed that in acase where the composition according to the embodiment of the presentinvention is used, the desired effect is obtained.

Through the comparison between Examples 1 and the like and Examples 29,32, and 34, it has been confirmed that the effect of the presentinvention is further improved in a case where the content of the iodicacid compound is 0.01% to 5.00% by mass with respect to the total massof the composition.

Through the comparison between Examples 1 and the like and Examples 12and 38, it has been confirmed that the effect of the present inventionis further improved in a case where the alkyl groups represented by R¹to R⁴ in Formula (1) have one to fifteen carbon atoms.

Through the comparison between Examples 1 and the like and Examples 12and 38, it has been confirmed that the effect of the present inventionis further improved in a case where the alkyl groups represented by R¹to R⁴ in Formula (1) have four to fifteen carbon atoms in total.

Through the comparison between Examples 1 to 4 and Examples 6 to 12, ithas been confirmed that the effect of the present invention is furtherimproved in a case where the alkyl groups represented by R¹ to R⁴ havefour to seven carbon atoms in total. Through the comparison betweenExamples 1 to 4 and Examples 6 to 12, it has been confirmed that theeffect of the present invention is further improved in a case where R¹to R⁴ each represent an alkyl group selected from the group consistingof an alkyl group having one carbon atom which may have a substituentand an alkyl group having two carbon atoms which may have a substituent,at least one of R¹, R², R³, or R⁴ is an alkyl group having one carbonatom which may have a substituent, and at least one of R¹, R², R³, or R⁴is an alkyl group having two carbon atoms which may have a substituent.

Through the comparison between Examples 1 to 4 and 6 to 10 and Examples11 to 12 and 38, it has been confirmed that the effect of the presentinvention is further improved in a case where the specific compoundincludes at least one compound selected from the group consisting of anethyltrimethylammonium salt, a diethyldimethylammonium salt, amethyltriethylammonium salt, a trimethyl(hydroxyethyl)ammonium salt, amethyltributylammonium salt, a dimethyldipropylammonium salt, abenzyltrimethylammonium salt, a benzyltriethylammonium salt, and atriethyl(hydroxyethyl)ammonium salt.

Through the comparison between Examples 1 and 13 and Examples 14 and 15,it has been confirmed that the effect of the present invention isfurther improved in a case where X^(n-) in Formula (1) is a hydroxideion or a chloride ion.

Through the comparison between Examples 1 and the like and Examples 35and 36, it has been confirmed that the effect of the present inventionis further improved in a case where the content of the specific compoundis 0.001% to 2.00% by mass with respect to the total mass of thecomposition.

Through the comparison between Examples 1 to 4 and 18 to 20 and Examples21 to 25, it has been confirmed that the effect of the present inventionis further improved in a case where the pH of the composition is 3.0 to9.0.

Through the comparison between Examples 1 to 4 and Examples 18 to 20, ithas been confirmed that the effect of the present invention is furtherimproved in a case where the pH of the composition is 4.0 to 8.0.

Through the comparison between Examples 1 and the like and Examples 5and 35, it has been confirmed that the metal residue removability isfurther improved in a case where the composition further contains achloride ion.

Through the comparison between Examples 1 and the like and Examples 5,13, 26 to 32, and 35, it has been confirmed that the metal residueremovability is further improved in a case where the content of thechloride ion is 0.001 to 10 ppm by mass with respect to the total massof the composition.

Through the comparison between Examples 28 and 31 and Examples 5, 27,29, and 35, and the comparison between Examples 36 and 37 and Examples13, 26, 30, and 32, it has been confirmed that the metal residueremovability is further improved in a case where the mass ratio of thecontent of the iodic acid compound to the content of the chloride ion is1.0 × 10⁴ or more.

Through the comparison between Examples 1 and Examples 16 to 17, it hasbeen confirmed that the effect of the present invention is furtherimproved in a case where the iodic acid compound includes at least onecompound selected from the group consisting of orthoperiodic acid andmetaperiodic acid.

EXPLANATION OF REFERENCES

10 a: wiring board before recess etching treatment of wiring 10 b:wiring board after recess etching treatment of wiring 12: insulatingfilm 14: barrier metal layer 16: Ru-containing wiring line 18: recess20, 30: object to be treated 22: substrate 24: Ru-containing film 26:outer edge 32: substrate 34: Ru-containing film 36: etching stop layer38: interlayer insulating film 40: metal hard mask 42: hole 44: interiorwall 44 a: cross-sectional wall 44 b: bottom wall 46: dry etchingresidue

What is claimed is:
 1. A composition comprising: at least one iodic acidcompound selected from the group consisting of periodic acid, iodicacid, and salts thereof; and a compound represented by Formula (1),

in Formula (1), R¹ to R⁴ each independently represent an alkyl groupwhich may have a substituent, R¹ to R⁴ do not represent the same groupall together, X^(n-) represents an n-valent anion, and n represents aninteger of 1 to
 3. 2. The composition according to claim 1, furthercomprising: a chloride ion.
 3. The composition according to claim 2,wherein a content of the chloride ion is 1 ppt by mass to 1% by masswith respect to a total mass of the composition.
 4. The compositionaccording to claim 2, wherein a mass ratio of a content of the iodicacid compound to the content of the chloride ion is 1.0 × 10⁴ or more.5. The composition according to claim 1, wherein a content of the iodicacid compound is 0.01% to 5.00% by mass with respect to a total mass ofthe composition.
 6. The composition according to claim 1, wherein thenumber of carbon atoms in the alkyl group is 1 to
 15. 7. The compositionaccording to claim 1, wherein the total number of carbon atoms in R¹ toR⁴ in Formula (1) is 4 to
 15. 8. The composition according to claim 1,where R¹ to R⁴ each represent an alkyl group selected from the groupconsisting of an alkyl group having one carbon atom which may have asubstituent and an alkyl group having two carbon atoms which may have asubstituent, at least one of R¹, R², R³, or R⁴ is an alkyl group havingone carbon atom which may have a substituent, and at least one of R¹,R², R³, or R⁴ is an alkyl group having two carbon atoms which may have asubstituent.
 9. The composition according to claim 1, wherein thecompound represented by Formula (1) includes at least one compoundselected from the group consisting of an ethyltrimethylammonium salt, adiethyldimethylammonium salt, a methyltriethylammonium salt, atrimethyl(hydroxyethyl)ammonium salt, adimethylbis(2-hydroxyethyl)ammonium salt, amethyltris(2-hydroxyethyl)ammonium salt, a methyltributylammonium salt,a dimethyldipropylammonium salt, a benzyltrimethylammonium salt, abenzyltriethylammonium salt, and a triethyl(hydroxyethyl)ammonium salt.10. The composition according to claim 1, wherein n in Formula (1) is 1.11. The composition according to claim 1, wherein X^(n-) in Formula (1)is a hydroxide ion, a chloride ion, a fluoride ion, or a bromide ion.12. The composition according to claim 1, wherein a content of thecompound represented by Formula (1) is 0.001% to 2.00% by mass withrespect to a total mass of the composition.
 13. The compositionaccording to claim 1, wherein a pH of the composition is 3.0 to 9.0. 14.The composition according to claim 1, wherein a pH of the composition is4.0 to 8.0.
 15. The composition according to claim 1, wherein thecomposition is used for removing a ruthenium-containing substance on asubstrate.
 16. A method for treating a substrate, comprising: a step Aof removing a ruthenium-containing substance on a substrate by using thecomposition according to claim
 1. 17. The method for treating asubstrate according to claim 16, wherein the step A is a step A1 ofperforming a recess etching treatment on a ruthenium-containing wiringline disposed on a substrate by using the composition, a step A2 ofremoving a ruthenium-containing film at an outer edge portion of asubstrate, on which the ruthenium-containing film is disposed, by usingthe composition, a step A3 of removing a ruthenium-containing substanceattached to a back surface of a substrate, on which aruthenium-containing film is disposed, by using the composition, a stepA4 of removing a ruthenium-containing substance on a substrate, whichhas undergone dry etching, by using the composition, or a step A5 ofremoving a ruthenium-containing substance on a substrate, which hasundergone a chemical mechanical polishing treatment, by using thecomposition.
 18. The composition according to claim 3, wherein a massratio of a content of the iodic acid compound to the content of thechloride ion is 1.0 × 10⁴ or more.
 19. The composition according toclaim 2, wherein a content of the iodic acid compound is 0.01% to 5.00%by mass with respect to a total mass of the composition.
 20. Thecomposition according to claim 2, wherein the number of carbon atoms inthe alkyl group is 1 to 15.